Microbiota and its antibiotic resistance profile in avocado Guatemalan fruits (Persea nubigena var. guatemalensis) sold at retail markets of Ibarra city, northern Ecuador.

Introduction: Avocados are typically sold in unsanitary conditions at the retail markets in Ecuador, which can raise the risk of microbial contamination. These microorganisms could exhibit multi-antibiotic resistance (MAR), being a serious threat concern to human health. In this study, we aimed to evaluate the microbiota and its antibiotic resistance profile in avocado Guatemalan fruits (Persea nubigena var. guatemalensis), at ripe stage: immature, firm light green (ready to eat in 4 days), peel (AFPE) and pulp (AFPU), and mature intense green (ready to eat) peel (AMPE) and pulp (AMPU), to gain baseline information on the prevalence of MAR bacteria. Methods: Culture-independent (16S rRNA metagenomics) and culture-dependent approach (to detect specific indicator microorganisms) were used. Moreover, antibiotic susceptibility of selected target indicator bacteria was assessed providing information about the antibiotic resistance (AR) among the groups. Results: Based on 16S rRNA gene metagenomic analysis, over 99.78% of reads were classified as bacteria in all samples. Shannon diversity index varies from 1.22 to 2.22, with the highest bacterial population assigned to AFPE samples (1327 species). The highest microbial counts of indicator Staphylococcus spp. (STAPHY), Enterobacter spp. (ENT), and Listeria spp. (LIST), were detected in AMPE samples. Thirty percent of the selected STAPHYs, and 20.91% of Enterobacter (ENT) clones were resistant to various classes of antibiotics. The MAR index varies between 0.25 to 0.88 and was clone-, and fruit ripe stage-dependent. Conclusions: The results indicated that ready to eat avocados contained detectable levels of MAR bacteria, including methicillin resistant (MR)-STAPHY, which may act as a potential vector for the spread of antibiotic resistance. To achieve the increase of the production and marketing of Fuerte cultivar in Ecuador, it is vitally important to consider valuable strategies to protect the fruits at the early ripe stage in future. Thus, it is crucial to set up efficient control measures and develop coordinated strategies to guarantee the microbiological quality of the food.

Prevalence of Plasmid-Associated Tetracycline Resistance Genes in Multidrug-Resistant Escherichia coli Strains Isolated from Environmental, Animal and Human Samples in Panama.

Antimicrobial resistance bacteria are nowadays ubiquitous. Its presence has been reported in almost every type of source, from water for agricultural and recreative use, water distribution pipes, and wastewater, to food, fomites, and clinical samples. Enterobacteriaceae, especially Escherichia coli, are not the exception, showing an increased resistance to several antibiotics, causing a global health and economic burden. Therefore, the monitoring of fecal microbiota is important because it is present in numerous reservoirs where gene transfer between commensal and virulent bacteria can take place, representing a potential source of resistant E. coli. In this work, antibiotic resistance profiles of 150 E. coli isolates from environmental, animal, and human samples, collected in three rural areas in Panama, were analyzed. A total of 116 isolates were resistant to at least one of the nine antibiotics tested. Remarkably, almost 100% of these exhibited resistance to tetracycline. Plasmid-associated tetA and tetB genes were detected in 42.86% of the isolates analyzed, tetA being the most prevalent. These results suggest that tetracycline resistance would be used as a convenient indicator of genetic horizontal transfer within a community.

Serratia marcescens SCH909 as reservoir and source of genetic elements related to wide dissemination of antimicrobial resistance mechanisms.

Serratia marcescens SCH909 is a multidrug resistant strain isolated in 1988 harboring three class 1 integrons. We wondered if these integrons were retained over time and if there were other antimicrobial resistant determinants contributing to its multidrug resistant profile. Genomic analysis showed a fourth multidrug resistance integron, a Tn7 transposon with dfrA1-sat2-ybeA-ybfA-ybfB-ybgA gene cassettes in the variable region. Insertion sequences were involved in the genesis of novel composite transposons in the L4 subtype plasmid pSCH909, such as Tn6824 carrying an arsenic regulon and two head to head class 1 integrons surrounded by two complete IS1. Remarkably, a novel chromosomal genomic island, SmaR, was identified, closely related to Multiple Antimicrobial Resistance Regions (MARR), usually found in AbaR0-type and AbGRI2-0 from global clones of Acinetobacter baumannii, and in M-type plasmids circulating in Enterobacteriaceae. Maintenance studies showed that the three class 1 integrons were maintained over 1 month without antimicrobial pressure. Since S. marcescens is considered a relevant nosocomial pathogen that can have a wide range of niches - human, plant, animal, soil and inanimate surfaces, our findings support the ability of this species to capture, maintain and spread a broad variety of antimicrobial resistance elements.

Integron mediated multidrug resistance in extended spectrum beta-lactamase producing clinical isolates of Klebsiella pneumoniae

The present study describes integron mediated multiple antibiotic resistance in extended-spectrum β-lactamase producing clinical isolates of Klebsiella pneumoniae. One hundred and four clinical isolates of K. pneumoniae from two Iranian hospitals were screened for extended-spectrum β-lactamase production and susceptibility of the extended-spectrum β-lactamase producing isolates was determined to 17 antibiotics by disc diffusion. Presence of integron classes 1, 2 and 3 was detected by PCR and integrase specific primers. Isolates harboring class 1 integron were then screened for variable regions using PCR. Fifty isolates (48%) produced extended-spectrum β-lactamases among which, 22 (44%) harbored class 1, 3 (6%) carried class 2 and none contained class 3 integons. Integron carriage was significantly associated with higher rates of multiple antibiotic resistance in extended-spectrum β-lactamase producing clinical isolates of K. pneumoniae. Integron harboring isolates were more resistant to aztreonam (51.3%), ceftazidime (42.6%), cefotaxime (43.3%), cefepime (24.6%), kanamycin (43.2%), tobramycin (30.7%), norfloxcacin (32%) and spectinomycin (25.6%) compared to the organisms without integrons. On the other hand, resistance to nitrofurantoin and streptomycin was significantly higher among the integron negative isolates. PCR amplification of class1 integron variable regions revealed 9 different sized DNA fragments and isolates with similar profiles for class 1 integron variable regions showed the same antibiotic resistance phenotypes.

Integron mediated multidrug resistance in extended spectrum beta-lactamase producing clinical isolates of Klebsiella pneumoniae.

The present study describes integron mediated multiple antibiotic resistance in extended-spectrum ß-lactamase producing clinical isolates of Klebsiella pneumoniae. One hundred and four clinical isolates of K. pneumoniae from two Iranian hospitals were screened for extended-spectrum ß-lactamase production and susceptibility of the extended-spectrum ß-lactamase producing isolates was determined to 17 antibiotics by disc diffusion. Presence of integron classes 1, 2 and 3 was detected by PCR and integrase specific primers. Isolates harboring class 1 integron were then screened for variable regions using PCR. Fifty isolates (48%) produced extended-spectrum ß-lactamases among which, 22 (44%) harbored class 1, 3 (6%) carried class 2 and none contained class 3 integons. Integron carriage was significantly associated with higher rates of multiple antibiotic resistance in extended-spectrum ß-lactamase producing clinical isolates of K. pneumoniae. Integron harboring isolates were more resistant to aztreonam (51.3%), ceftazidime (42.6%), cefotaxime (43.3%), cefepime (24.6%), kanamycin (43.2%), tobramycin (30.7%), norfloxcacin (32%) and spectinomycin (25.6%) compared to the organisms without integrons. On the other hand, resistance to nitrofurantoin and streptomycin was significantly higher among the integron negative isolates. PCR amplification of class1 integron variable regions revealed 9 different sized DNA fragments and isolates with similar profiles for class 1 integron variable regions showed the same antibiotic resistance phenotypes.

Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in Natal, Brazil

Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50 percent) presented multiple antibiotic resistance to ampicillin (90 percent) and amikacin (60 percent), while two strains (20 percent) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90 percent, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in natal, brazil.

Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50%) presented multiple antibiotic resistance to ampicillin (90%) and amikacin (60%), while two strains (20%) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90%, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

Antibiotic resistance of Vibrio parahaemolyticus isolated from pond-reared Litopenaeus vannamei marketed in Natal, Brazil

Ten out of fifty fresh and refrigerated samples of shrimp (Litopenaeus vannamei) collected from retailers in Natal (Rio Grande do Norte, Northeastern Brazil) tested positive for Vibrio parahaemolyticus. The Kanagawa test and multiplex PCR assays were used to detect TDH and TRH hemolysins and the tdh, trh and tlh genes, respectively. All strains were Kanagawa-negative and tlh-positive. Antibiotic susceptibility testing was done for seven antibiotics by the agar diffusion technique. Five strains (50%) presented multiple antibiotic resistance to ampicillin (90%) and amikacin (60%), while two strains (20%) displayed intermediate-level resistance to amikacin. All strains were sensitive to chloramphenicol. Intermediate-level susceptibility and/or resistance to other antibiotics ranged from 10 to 90%, with emphasis on the observed growing intermediate-level resistance to ciprofloxacin. Half our isolates yielded a multiple antibiotic resistance index above 0.2 (range: 0.14-0.29), indicating a considerable risk of propagation of antibiotic resistance throughout the food chain.

Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana) raised in Malaysia

A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana) raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3 percent) cases of sensitivity and 61 (7.3 percent) cases of partial sensitivity. Meanwhile, 297 (35.4 percent) bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR) index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. Additionally, high percentages of heavy metal resistance among these isolates were observed, with values ranging from 85.0 to 100.0 percent. The current results provided us information on bacterial levels of locally farmed bullfrogs exposed to copper, cadmium, chromium as well as 21 types of antibiotics.(AU)

Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana) raised in Malaysia

A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana) raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3%) cases of sensitivity and 61 (7.3%) cases of partial sensitivity. Meanwhile, 297 (35.4%) bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR) index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. Additionally, high percentages of heavy metal resistance among these isolates were observed, with values ranging from 85.0 to 100.0%. The current results provided us information on bacterial levels of locally farmed bullfrogs exposed to copper, cadmium, chromium as well as 21 types of antibiotics.

Characterization of Shigella spp. by antimicrobial resistance and PCR detection of ipa genes in an infantile population from Porto Velho (Western Amazon region), Brazil

The incidence of Shigella spp. was assessed in 877 infants from the public hospital in Rondônia (Western Amazon region, Brazil) where Shigella represents the fourth cause of diarrhea. Twenty-five isolates were identified: 18 were Shigella flexneri, three Shigella sonnei, three Shigella boydii and one Shigella dysenteriae. With the exception of S. dysenteriae, all Shigella spp. isolated from children with diarrhea acquired multiple antibiotic resistances. PCR detection of ipa virulence genes and invasion assays of bloody diarrhea and fever (colitis) were compared among 25 patients testing positive for Shigella. The ipaH and ipaBCD genes were detected in almost all isolates and, unsurprisingly, all Shigella isolates associated with colitis were able to invade HeLa cells. This work alerts for multiple antibiotic resistant Shigella in the region and characterizes presence of ipa virulence genes and invasion phenotypesin dysenteric shigellosis.